The toxic effects of piperine against Trypanosoma cruzi: ultrastructural alterations and reversible blockage of cytokinesis in epimastigote forms

Abstract

In a previous work, we have investigated the effects of piperine and several of its chemical derivatives on the proliferation of the protozoan parasite Trypanosoma cruzi. It was observed that natural piperine is more active against intracellular amastigotes than axenically grown epimastigotes with IC50 values of 4.91 and 7.36 microM, respectively. Despite its superior trypanocidal activity against the intracellular amastigotes, here, we show that piperine did not enhance microbiocidal characteristics of murine peritoneal macrophages (Mø) based on nitric oxide production. As shown by light and electron microscopy analysis, epimastigotes treated with sublethal concentrations of piperine presented a reversible cell cycle arrestment and become round shaped, with swelling of the mitochondrion matrix and intense intracellular vacuolization with structures displaying complex membrane invaginations. Similar to the effects of exposing epimastigotes to the antitumor and microtubule stabilizer taxol, multiplication of cell organelles such as the flagellum, kinetoplast, and nucleus occurred, but division into daughter cells was impaired. Unlike the effects caused by the anti-microtubular vinca alkaloids vincristine and vinblastine, which also induce cytokinesis arrestment in T. cruzi epimastigotes, piperine did not induce the formation of giant multinucleated cells. The data reinforce the selectivity of the mechanisms of action of piperine against T. cruzi.

Trypanocidal activity of Piper arboreum and Piper tuberculatum (Piperaceae)

“…Other amides from Piper species are among the natural products of interest since many of it compounds display a broad range of antiprotozoal activities (Raay et al, 1999;Bodiwala et al, 2007;Freire-de-Lima et al, 2008). Kapil (1993) reported an investigation of piperine (amide 6) activity against promastigote forms of Leishmania donovani.…”

Contributions of Ultrastructural Studies to the Cell Biology of Trypanosmatids: Targets for Anti-Parasitic Drugs

“…In some parasites, more than one individualized kinetoplast can be observed, mimicking the effects of cytoskeleton inhibitors. In other parasites, however, up to three kDNA bars can be seen inside the same mitochondrion [84] (Fig. 2J).…”

“…However, changes in the shape of the parasites, the presence of multiple flagellae, aberrant cell types with multiple kinetoplasts and absence of a nucleus were observed; these changes are probably due to incomplete differentiation and cytokinesis [74,75,84,92,102,103]. Disorganization of the sub-pellicular microtubule layer was only observed in amastigotes of T. cruzi incubated in the presence of reversed amidines [22,23].…”

Piperine, its Analogues and Derivatives: Potencial as Antiparasitic Drugs

“…Verificou-se, por exemplo, a importância do tamanho do espaçador de cinco átomos de carbono, presente entre o anel aromático (subunidade A) e a piperamida (subunidade C) da estrutura da piperina (Figura 2), através da síntese dos derivados (20) Dando continuidade à investigação sobre a atividade tóxica da piperina contra T. cruzi, o mesmo grupo de pesquisa realizou estudos de microscopia eletrônica de varredura e de transmissão em epimastigotas tratados com doses sub-letais (5-8 μM de piperina para, a partir das observações das alterações ultraestruturais ocorridas no parasito, poder inferir sobre os prováveis mecanismos de ação desta amida natural frente ao T. cruzi. 47 Conforme descrito na literatura, um dos mecanismos utilizados por macrófagos para combater amastigotas do T. cruzi é a produção de NO. 74 Como a piperina é capaz de inibir a formação deste óxido, 75 sua atividade deve estar diretamente relacionada a uma ação no parasito e não indiretamente pela indução do macrófago.…”

“…Verificou-se também neste trabalho o efeito tripanostático da amida natural sobre as formas epimastigotas, evidenciada pela interferência da piperina na citocinese do parasito. 47 Em trabalho realizado posteriormente por outro grupo de pesquisa, foi descrita a avaliação da atividade da piperina e de outras piperamidas naturais, isoladas de Piper tuberculatum e Piper arboreum, contra a forma epimastigota de T. cruzi. 76,77 Do conjunto de resultados descritos nestes trabalhos, destacam-se as atividades antiepimastigota dos análogos naturais da piperina, piperilina (37) e 4,5-dihidropiperiline (38), isoladas das folhas de P. arboreum (CI 50 = 6,57 M e 210,0 M, respectivamente).…”